Bridge



im. swonenn, osMANsFIELD, omo.

BRIDGE.

` Speclcaticn of Letterslatentw i Patented Dec. 27, 1921.

sumisa nit :une 9, 1Mo. serial No. 337,356.

To all whom it mq/y concern.' Y

`Be itknown that Il #llamas M. SwoNGER, a citizen of the United States,residing at Mansfield, in the county of Richland and State of Ohio, haveinvented certain new and useful Improvements in Bridges, of which thefollowing is a specification, reference being had tothe accompanyingdrawings.

This invention relates to bridge constructions and more particularly tobridge constructions of the t pe wherein spans are used connecting spacepiers or abutments.

An important object of the invention is to provide a bridge constructionwherein the spans are held in position mainly by their own weight, andwhich consequently reuires the minimum amount of tying own,- which formsone of the most expensive portions of bridge construction.

A further object is to provide a bridge construction which may belocated with minimum loss of time in plaoin of the spans in positionwhen the piers are completed.

Other objects and advantages will become apparent throughout the courseof the following description.

In the accompanying drawings, wherein for the purpose of illustrationare shown preferred embodiments of my invention and wherein likenumerals designate like parts throughout Fi re 1 is an elevational viewillustrating a bridge construction arran ed in accordance with anembodiment o my invention and of a single s an type; and

Fig. 2 is an e evational view illustrating my improved bridge structureembodying a plurality of spans.

Referring now more particularly to the drawings, the numeral 10indicates abutments having their opposing faces tapered as at 11, theabutments being widest at the base l0 thereof. These abutments inpractice will be disposed with their rear or outer faces engaging theembankments of the cut which the bridge is to span.

Spans 14 are provided, each com rising a pair of similar sections 14hinged y connected at their central lower ends as at 15. The ends of thespans are tapered to corres ond to the taper of the faces 11 of theabutments against which they are designed to rest.

In the construction of the bridge in accordance with my invention, duecalculations are first made as toexpansibility of the materials used inthe formation of the span sections and of the abutments and the lengthof the span made accordingly, so that when the materials forming theabutments and span are contracted to the maximum, the central verticalmeeting edges 17 of the span sections 14 will be engaged in the positionshown in the drawings. It will be obvious that expansion of theabutments and span sections will cause the span to rise slightly at thecenter at its pivot point, this tendency to rise being assisted by thefact that the bottom of the span sections 15 are inclined slightlyupwardly toward the center as at 14, The foregoing constructioncompletely prevents buckling of the span 14 and at the same time placesthe major portion of the weight of the span in an endwise directionagainst the abutments 11.

When the distance to be bridged is too great for the use of a singlespan of the type mentioned, a *central pier 18 may be employed havingits sides inclined as at 19 in the opposite dlrection from theinclination of the abutments that these piers face. Where intermediatepiers are employed, I prefer that the central pier shall be of greaterheight than the abutments at the ends of the bridge so that thecompleted bridge will incline upwardly toward the center thereof. Bythis construction the principle of arch construction is applied, themajor portion of the weight being disposed at the ends of the bridge.The pier need not of itself be made higher than the abutments 10 as thisinclination may be taken care of by the placement of the spans 14.

The piers and abutments may likewise, if so desired, be provided withshoulders 20 upon which the ends of the span 14 rest. In the completionof the bridge any suitable flexible floor covering 21 may be employed.It will, however, be observed that the rise caused at the centralportions of the span by said expansion is not suflicient to matcriallydisarrange the floor covering of any type which may be employed.

It will be obvious to those familiar with the art that as many changesare possible in the manner of construction of the spans and abutmentsshown, the drawings and descriptions accompanying the same are intendedto be interpreted merely in an illustrative and not a limiting sense,and I accordingly do not confine myself to the specific structurehereinbefore described, but may make any such changes without departingfrom the spirit of the invention or the scope of the subjoined Claims.

Having now described my invention,

edges of their meeting ends, the outer ends of each span being angled toit the :ingle of divergence of the abutment faces.

2. In :i bridge, a. pair of abutinents :1nd :L

beam engaged therebetween and comprising L plurality of sectionshingedly connected at the lower edges of their meeting ends.

In testimony whereof l hereunto :LHiX my signature.

JAMES M SWONGER.

